# -*- coding: utf-8 -*-#
#-------------------------------------------------------------------------------
# 建立者:        潘炎珍  
# Name:         demo11
# Description:
# Author:       98745
# Date:         2019/2/28
#-------------------------------------------------------------------------------

d={}
print(d.setdefault('name','bill'))
print(d)
print(d.setdefault('name','mike'))
print(d)
print(d.setdefault('age'))
print(d)